<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <title>Document</title>
        <style>
            div {
                width: 100px;
                height: 100px;
                background: red;
            }
            p {
                width: 100%;
                height: 100%;
                padding: 10px;
                background: green;
            }
        </style>
    </head>
    <body>
        <div>
            <p></p>
        </div>
    </body>
</html>
